气候变化领域集成服务门户(CCPortal): Linking the Madden–Julian Oscillation, tropical cyclones and westerly wind bursts as part of El Niño development

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DOI	10.1007/s00382-021-05757-1
	Linking the Madden–Julian Oscillation, tropical cyclones and westerly wind bursts as part of El Niño development
	Liang Y.; Fedorov A.V.
发表日期	2021
ISSN	0930-7575
起始页码	805
结束页码	824
英文摘要	Westerly wind bursts (WWBs) that occur over the western and central equatorial Pacific are believed to play an important role in ENSO dynamics; however, the mechanisms of WWB generation are still debated. In this study we investigate a link between the Madden–Julian Oscillation (MJO) and WWBs that involves tropical cyclones (TCs) generated within the MJO sufficiently close to the equator. Using an atmospheric reanalysis and WWB composites, we first isolate WWBs that occur (1) between December and April and (2) between May and November, corresponding to the onset and development stages of El Niño. We find that during the onset stage, a warm background sea surface temperature (SST) anomaly develops over the central-western equatorial Pacific with anomalous westerly winds to its west, which draws the MJO convective activity in the southern hemisphere closer to the equator. As a result, westerly wind anomalies associated with the MJO together with tropical cyclones embedded in the MJO induce strong WWBs (during neutral conditions the MJO usually takes a more southerly route and cannot induce strong bursts). Subsequently, during the development stage of El Niño, there develops an anomalous warming in the central-eastern equatorial Pacific, also with corresponding westerly winds, which steers the MJO path, now in the northern hemisphere, toward the equator, strengthening the MJO signal over the central equatorial Pacific. Consequently, tropical cyclones modulated by the MJO move closer to the equator and farther east, facilitating WWBs. Thus, MJO events with embedded tropical cyclones are crucial for the generation process of WWBs during the onset and development of El Niño. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
英文关键词	El Niño; Madden-Julian oscillation; Tropical cyclones; Westerly wind bursts
来源期刊	Climate Dynamics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/183487
作者单位	Department of Earth and Planetary Sciences, Yale University, New Haven, CT, United States; LOCEAN/IPSL, Sorbonne University, Paris, France
推荐引用方式 GB/T 7714	Liang Y.,Fedorov A.V.. Linking the Madden–Julian Oscillation, tropical cyclones and westerly wind bursts as part of El Niño development[J],2021.
APA	Liang Y.,&Fedorov A.V..(2021).Linking the Madden–Julian Oscillation, tropical cyclones and westerly wind bursts as part of El Niño development.Climate Dynamics.
MLA	Liang Y.,et al."Linking the Madden–Julian Oscillation, tropical cyclones and westerly wind bursts as part of El Niño development".Climate Dynamics (2021).